The invention relates to a method for calibrating an autostereoscopic display system. More specifically, the invention relates to a method for calibrating an autostereoscopic display system having a display device and an imaging array.
According to the general principles of stereoscopy, an impression of spatial depth is generated by presenting to the two eyes of a viewer different images that show the same scene from slightly different perspectives, which reflect the parallax difference between the left and right eye of the viewer.
Whereas conventional systems for presenting different images to the left and right eyes of the viewer employ headsets, shutter glasses or polarisation glasses, which may be disturbing for the viewer, autostereoscopic or glasses-free 3D display systems do not require such additional means but permit to view stereoscopic images “with the naked eye”.
U.S. Pat. No. 6,302,541 B1 and WO 2008/011888 A1 describe methods for the autostereoscopic representation of images, wherein image information of separate channels for a right eye and a left eye of a viewer is displayed in interleaved segments on a screen, and an imaging array consisting of a lens array is disposed for deflecting light emitted from the screen such that the image information of each channel is visible only for one eye of the viewer.
In order to provide separate image information for the left and right eyes of the viewer, geometrical and/or optical parameters of the display device and the imaging array and their relative arrangement must be known.
In case an imaging array is mounted during manufacture of an autostereoscopic display and is not intended to be repeatedly detached and mounted by a user, the alignment and/or calibration of the relative arrangement may be performed during manufacturing of the system, e.g. using dedicated alignment equipment and depending on visual inspection by trained personal.
Autostereoscopic display systems that have an imaging array which is user mountable and detachable and/or which is switchable between an active mode and an inactive mode have the advantage that the user may choose to use a display device of the system in a 2D-mode or, by mounting the imaging array and/or switching the imaging array to active mode, in a 3D-mode.